Belt-tightener.



L. A. TIRRILL.

BELT TIGHTENER. AIPLIGATION FILED JAN. 30, 1905.

Patented Sept. 30,1913.

2 SHEETS-SHEET 1.

BELT TIGHTENER. APPLICATION IILBD JAN. 30, 1905.

Patented Sept. 30; 1913,

2 SHEETS-SHEET 2.

Inventor Lonard JT. irril W Y -.UNITED STATES PATENT orrrcu.

monsnn A. TIRBILL, or print, nssshonusnrrs,

remade no ennui-cu; nrsc'rmc COMPANY, A coRPoBAT'roN on NEW YORK.isnnr-rrenmmmn.

routes.

spec-mama- 01 Letters Patent.

Phtenteds'ept. at 1am;

Application filed! January 36, 1805.. Serial-No. 243,198.

Improvements in Belt-Tighteners, of which" the following is aspecification;

My present invention has for its object the production of a simple andefficient construction for supporting a belt tightener oi" the likewhich can be readily applied to dynamo-electric machinesstructi-on. 1

My invention comprises novel features of construction and arrangement,all of whichare pointedout with particularity in the claims annexed toand forming a partof this specification.

For a better" understanding of my invention, however, reference may behad' to the accompanying drawings and description in which Ihaveillustrated and described a structure in which my invention may beembodied.

Of the drawings, Figure 1 shows an end elevation of a dynamo-electricmachine equipped with'a belt tigzhtener supported in aeeor ance with myinvention; Fig. 2 is a side elevation of the machine shown in Fig. 1;:Fig; 3 is a section on the line 3 3;- of Fig. 1; Fig. 4 is an endelevation of a:

of ordinary conshaft and counter shaft are connected by two gears; Fig.-5 is a View taken similar to Fig. 2', with: parts in section, on line 55 of Fig. 4; and Fig. 6 is a sectional View showing a gear which may beused with the construction shown in Figs. 4' and 5..

In the drawings, 1 represents the field ring or frame of a dyna-moelectric' machine. The field ring I is provided with the usualsupporting feet 2. End members or heads 3 and 44 are secured against theends of the fiel d ring 1. .The armature" shaft 5 is journaled inbearings carried by the end mem bers 3 and 4 in the usual manner. In theconstruction shown in Figs. 1 and 2 one end of the armature shaft hassecured to it a power-transmitting policy 6 which drives or is driven bya flexible belt 7 .An annular member or ring oryoke or plate 8concentric with the armature shaft 1s located adjacent the. pulley andat the end of the armature shaftfi. The ring 8 is preferably providedwith apertured lugs LEONARD A. TrRmLL,

or feet a Equally s acedbolts 10,- whichform angularly spacezoinzts ofattachment,

'feet 9 in order to'secure the ring; 8 to the field rin the bolts flangeof the end member 41 and are thus the annular member 8- in position. Theinner periphery of the member 8 is cylindrical and machined. The outerend armatureshaft andis also machined. IHJ

the outer end' surface and inner periphery respectively as is clearlyshown in Fi 3. The channel- 12 has a function to per orn'i two machinedsurfaces of the member areconnected: by a convexly-curved surface sogin: crosssection, as clearly appears in Fi r. 3. The belt ti htener'pulley on idler u lley @15 is mountea ona; shaft 16 carrie in a iframeI7 The frame 1-Z comprises two arms l8 and-19 which extendfrom a hub istud-shaft 21 carried'by a member 22. which is adj-ustably clamped tothe annular memher 8- by a set-screw 23; modified construction in whicharmature The inner arm 18 oat the; frame 17 is extended beyond the shaft16; A rod- 24 is ithe' arm' 18-. This rod passes through an i opening,formed for the purpose in amemher or anchor pin 25. which is adjfustablysecured to themember'B by a screw 26. The free end of the rod 24 isthreaded and carthe threaded portion 0-fthe rod and may be secured inany desired position by a locki nut28. .A: helical spring 29 surroundingthe F rod has one en'd bearing against the nut 27 J and the other endagainst the member The member 25 is provided with a portion- 30 whichabuts against the outer end surface of the member 8 and another portion31 at right angles tothe portion 30- which abuts against the innerperiphery of the member 8. A projection 32 from the portion 3-1 of themember 25 fits in the channel 12 formed in theend member 8 andassists inpositioningthe device 25-. It will be understood that the outersurfia'ce of the. porpass through the apertures of the lugs or' g 1'. Inthe construction illustrated 10 also pass through the annularemployed tosecure both the end. member 46' M1 order to reduce the machine worknecessary,-

'of the member are channeled at 11 and 12- that the member issubstantially triangular 20; The huls-20 is pivotally mounted on a,

rice a nut 27 which may be adjusted along surface of the ring isperpendicular to the which will be hereinafter pointed out. The

pivotal-lyconnected-to the extended end of tion 31 is curved to fit theinner periphery of the member 8. ,An inturned extension from the portion30 of the member 25 is formed with a threaded o ening in which theclamping screw or b The inner end of the screw or bolt 26 engages theconvexly-curved surface of the connection points for the arms 18 an 19be of different angular spacing from the spacing of the points ofattachment of the yoke to the frame, and in the construction shown inthe drawing are infinite in number. The rod 24 and spring 29 hold theulley 15 against the belt 7 with any desired pressure, regardless of theslight changes in the length of the belt,

which may whlch may occur from time to time on account of changes in thetemperature or moisture of atmosphere or the like. It will be observedthat the belt tightener construction shown and described can be appliedto dynamo-electric machines of the ordinary construction without anyfurther change than an increase in the length of the bolts 10.

In the construction shown in Figs; 4 and 5, the power-transmittingdevice carried by the armature shaft 5 of the motor is a spur gear 35instead of a pulley, as shown in Figs. 1 and 2. A member 36 which may besubstantially identical in construction with the member 22, but isusually somewhat heavier and stronger, carries a counter shaft 37. Agear wheel 38, usually considerably larger than the gear wheel 35, ismounted on the counter shaft 37, which meshes with the gear wheel 35. Asuitable device 37 is em ployed to lubricate the shaft 37. By reason ofthe difference in diameter of the gear wheels 35 and 38, the countershaft rotates considerably slower than the armature shaft, and thearrangement forms a speed-reducing device. The counter shaft 37 issecured in a slot 36' in the member 36, and may be moved toward and awayfrom the shaft 5 to permit the use of gears of different diameters.

In the construction shown in Figs. 4 and 5, the gear wheel 38 isintended to mesh with another gear wheel (not shown) and serves totransmit power from the machine to the gear wheel (not shown) or viceversa depending on whether the machine is employed as a motor or agenerator. In some transmitting member. sprocket wheel 39'shown in Fig.6 may be t 26 is located.

are sub-" I shaft in the same manner cases the gear wheel 38 may beprovided with means for driving a flex ble power- For instance, the

secured to the gear wheel 38 by the bolts 40 screwed into the threadedrecesses 41. The 4 seirocket wheel 39 drives a sprocket chain notshown).

-' It will be observed that the member 36 is angularly adjustable aboutthe armature as in the member 22,'and b this construction the gear wheel38 may e adjusted about the armature shaft whenever desirable.

What I claim as new and desire to'secure by Letters Patent of the UnitedStates, is-

1. In combination, an end plate of a dynamo-electric machine, aring-shaped member having lugs or feet with apertures therein, boltspassing through said apertures for securing said ring-shaped member inplace, and a belt tightener comprising an idler pulley, a pivotedsupport for said pulley, an abutment on which said support is mounted,and means for locking said abutment at any one of a plurality of pointson said ring-shaped member to change the position of the idler pulley.2. The combination of a pulley, a supporting shaft, a frame surroundingthe shaft with angularly spaced points of attachment, an idler pulley,an arm for the support of the idler pulley, a yoke with a plurality ofconnection points for the arm, and a tension device applied to the arm,substantially as described. Y

3. The combination of a pulley, a suppor ing shaft, a frame surroundingthe shaft with angularly spaced points of attachment, an idler ulley, anarm for the-support of the idler pulley, and a yoke with'a plurality ofconnection points for the arm with different angular spacing from thespacing of the points of attachment of the yoke to the frame,substantially as described. y

-4. The combination of a pulley, a supporting shaft, a frame surroundingthe shaft with angularly spaced points of attachment, an idler pulley,an arm for thesupport of the idler pulley, a yoke with a plurality ofconnection points for the arm, a tension spring for the idler arm and ananchor pin adapted to be attached at theconnection points provided forthe arm, substantially as described. i

5. In combination, an electric motor having a frame and an end-head, aplurality of equally spaced bolts for attaching said endhead to saidframe,'a belt-tightener comprising an idler-pulley, a pivoted supportfor said pulley, and a plate on which ,said support is mounted, saidplate being mounted on a bolt passing through the end-head into theframe, substantially as described.

In combination, an electric motor having a frame and an end-head, aplurality of substantially equally spaced bolts for at- ,through the endhead into taching said end headto said frame, a belttightener comprisingan idler-pulley, a pivoted support for said pulley, a ring'shaped membermounted on said bolts passing said frame, a tension device for saidsupport, and means for locking said pivoted support and said tensiondevice at any one of a plurality of points on, said ring shaped memberto change the position of the idler pulley.

7. In combination, an electric motor having a frame and an end-head, aplurality of substantially equally spaced bolts for attaching said endhead'to said frame, a belt tightener comprising an idler-pulley, apivoted support for said pulley, a ring-shaped member having lugs orfeet with apertures' therein, said bolts passing through said apertures'for securing said ring-shaped member in place, a'tension device for saidsupport,

LEONARD A. TIRRILL. Witnesses:

JOHN A. MCMANUS, J r.,

DUGALD MoK. MCKILLoP

